Interleukin 10 (IL10) is a major anti-inflammatory cytokine that acts as a master regulator of the immune response. A single nucleotide polymorphism rs3024505(C/T), located downstream of the IL10 gene, is associated with several aggressive inflammatory diseases, including systemic lupus erythematosus, Sjögren’s syndrome, Crohn’s disease, and ulcerative colitis. In such autoimmune pathologies, IL10-producing B cells play a protective role by decreasing the level of inflammation and restoring immune homeostasis. This study demonstrates that rs3024505 is located within an enhancer that augments the activity of the IL10 promoter in a reporter system based on a human B cell line. The common rs3024505(C) variant creates a functional binding site for the transcription factor STAT3, whereas the risk allele rs3024505(T) disrupts STAT3 binding, thereby reducing the IL10 promoter activity. Our findings indicate that B cells from individuals carrying the minor rs3024505(T) allele may produce less IL10 due to the disrupted STAT3 binding site, contributing to the progression of inflammatory pathologies.

The MPC 1 gene is involved in the transport of pyruvate into mitochondria, playing an important role in metabolic processes. Recently, it has been reported that higher MPC 1 expression correlates with an increased number of immune cells in human cervical and lung cancers, indicating an enhanced antitumor immune response. Reduced MPC 1 levels in gastric tumors are associated with a more severe disease course. Correlational analysis of the MPC 1 gene in human lung, hippocampus and frontal cortex tissue samples based on data from the GTEx database revealed associations of this gene with schizophrenia, non-small cell lung cancer, and immune diseases. Our experiments showed that the mRNA level of the MPC 1 gene in the non-small cell lung cancer cell line A549 increases 5-fold under the influence of the schizophrenia neuroleptic thioridazine. The observed elevation of MPC 1 level may cause tumor infiltration by immune cells, complementing the previously reported data indicating the ability of thioridazine to slow cell growth, induce apoptosis and reduce the ability of cells to migrate.

SLAMF1 encodes CD150, an immunoregulatory receptor involved in lymphocyte activation, T–B-cell interactions, and humoral immune responses. The SLAMF1 promoter polymorphism rs2295613(G>A) was previously associated with systemic lupus erythematosus (SLE) susceptibility in a Chinese case–control cohort. Here, we investigated the regulatory activity of rs2295613 in the transformed B-cell lines Raji and MP1 and in primary human CD19⁺ B cells. The rs2295613(A)-containing reporter showed higher promoter activity than the rs2295613(G)-containing reporter in all three cellular systems. Bioinformatic analysis predicted that the G to A substitution strengthens a pre-existing MYC-compatible motif. Substitutions disrupting the motif-containing region attenuated the rs2295613(A)-associated increase in reporter activity and reduced enrichment of the promoter fragment in anti-c-MYC DNA pull-down assays. Partial siRNA-mediated reduction in MYC mRNA also decreased the activity of the rs2295613(A)-containing reporter in Raji cells. Together, these findings identify rs2295613 as a functional SLAMF1 promoter variant in B-cell reporter systems and support a contribution of c-MYC-associated regulation to the enhanced activity of the rs2295613(A)-containing promoter.

Chromosomal rearrangements that lead to the formation of oncogenic gene fusions, such as EML4-ALK, are thought to arise from incorrect repair of double-strand breaks in DNA. However, the mechanisms and factors driving rearrangement formation remain poorly understood, and analysis of these processes is limited by detection methods that are labor-intensive, low-throughput, and not readily quantitative at single-cell resolution. Here, we developed a genetically encoded ALK reporter based on A549 lung adenocarcinoma cells, created by inserting an ALK-P2A-mCherry cassette into the endogenous ALK locus, so that induced EML4-ALK fusion activated mCherry fluorescence. Reporter activation yielded a readily quantifiable mCherry-positive subpopulation that could be measured and enriched by flow cytometry and correlated with EML4-ALK levels. Using this platform, we combined CRISPR-mediated rearrangement induction with knockdown of DNA repair factors using RNA interference. Of the factors involved in base excision repair, homologous recombination-related pathways and canonical non-homologous end joining, knockdown of the APEX1 gene encoding apurinic endonuclease 1 (APE1) selectively increased EML4-ALK levels both in the reporter cell line and in parental A549 cells. Together, this work provides a sensitive, single-cell A549-based ALK reporter platform and a framework for future studies aimed at identifying cellular and environmental factors that modulate oncogenic EML4-ALK rearrangement formation.